# std::time_get<CharT,InputIt>::get_monthname, std::time_get<CharT,InputIt>::do_get_monthname

From cppreference.com
< cpp‎ | locale‎ | time get

Defined in header `<locale>` |  |
public: iter_type get_monthname( iter_type beg, iter_type end, std::ios_base& str, std::ios_base::iostate& err, std::tm* t ) const; | (1) |
protected: virtual iter_type do_get_monthname( iter_type beg, iter_type end, std::ios_base& str, std::ios_base::iostate& err, std::tm* t ) const; | (2) |

1) Public member function, calls the protected virtual member function `do_get_monthname` of the most derived class.
2) Reads successive characters from the sequence `[`beg`,` end`)` and parses out the month name (possibly abbreviated), using the default format for month names expected by this locale, which is the same format as "%b" as used by the functions std::get_time, `time_get::get`, and the POSIX function `strptime()`.

If it finds abbreviated name, followed by the characters that are valid for the full name, it continues reading until it consumes all the characters for the full name or finds a character that isn't expected, in which case parsing fails even if the first few characters were a valid abbreviation.

The parsed month is stored in the std::tm field t->tm_mon.

If the end iterator is reached before a valid month name is read, the function sets std::ios_base::eofbit in err. If a parsing error is encountered, the function sets std::ios_base::failbit in err.

### Parameters

beg | - | iterator designating the start of the sequence to parse
end | - | one past the end iterator for the sequence to parse
str | - | a stream object that this function uses to obtain locale facets when needed, e.g. std::ctype to skip whitespace or std::collate to compare strings
err | - | stream error flags object that is modified by this function to indicate errors
t | - | pointer to the std::tm object that will hold the result of this function call

### Return value

Iterator pointing one past the last character in `[`beg`,` end`)` that was recognized as a part of a valid month name.

### Notes

This function is usually case-insensitive.

If a parsing error is encountered, most implementations of this function leave *t unmodified.

### Example

Run this code

    #include <ctime>
    #include <iostream>
    #include <iterator>
    #include <locale>
    #include <sstream>
    #include <string_view>

    void try_get_mon(std::string_view locale_name, std::string_view source)
    {
        try
        {
            std::locale::global(std::locale(locale_name.data()));
        }
        catch (std::runtime_error const& ex)
        {
            std::cout << "Cannot setup locale: " << locale_name << "\n"
                         "Exception: " << ex.what() << '\n';
            return;
        }

        std::cout << "Parsing the month out of '" << source
                  << "' in the locale " << std::locale().name() << '\n';
        std::istringstream str{source.data()};
        std::ios_base::iostate err = std::ios_base::goodbit;

        std::tm t;
        std::time_get<char> const& facet = std::use_facet<std::time_get<char>>(str.getloc());
        std::istreambuf_iterator<char> ret = facet.get_monthname({str}, {}, str, err, &t);
        str.setstate(err);
        std::istreambuf_iterator<char> last{};

        if (str)
        {
            std::cout << "Successfully parsed, month number is " << t.tm_mon;

            if (ret != last)
            {
                std::cout << ". Remaining content: ";
                std::copy(ret, last, std::ostreambuf_iterator<char>(std::cout));
            }
            else
                std::cout << ". The input was fully consumed";
        }
        else
        {
            std::cout << "Parse failed. Unparsed string: ";
            std::copy(ret, last, std::ostreambuf_iterator<char>(std::cout));
        }

        std::cout << '\n';
    }

    int main()
    {
        try_get_mon("ja_JP.utf8", "2月");
        try_get_mon("th_TH.utf8", "กุมภาพันธ์");
        try_get_mon("el_GR.utf8", "Φεβ");
        try_get_mon("el_GR.utf8", "Φεβρουάριος");
        try_get_mon("en_US.utf8", "Febrile");
    }

Possible output:

    Parsing the month out of '2月' in the locale ja_JP.utf8
    Successfully parsed, month number is 1. The input was fully consumed
    Parsing the month out of 'กุมภาพันธ์' in the locale th_TH.utf8
    Successfully parsed, month number is 1. The input was fully consumed
    Parsing the month out of 'Φεβ' in the locale el_GR.utf8
    Successfully parsed, month number is 1. The input was fully consumed
    Parsing the month out of 'Φεβρουάριος' in the locale el_GR.utf8
    Successfully parsed, month number is 1. The input was fully consumed
    Parsing the month out of 'Febrile' in the locale en_US.utf8
    Parse failed. Unparsed string: ile

### Defect reports

The following behavior-changing defect reports were applied retroactively to previously published C++ standards.

DR | Applied to | Behavior as published | Correct behavior
--- | --- | --- | ---
LWG 248 | C++98 | `eofbit` was not set upon reaching the end iterator | sets `eofbit` if a valid month name has not been read

### See also

get_time (C++11) | parses a date/time value of specified format (function template)

Retrieved from "https://en.cppreference.com/mwiki/index.php?title=cpp/locale/time_get/get_monthname&oldid=160214"